Expressions

Table of Contents



Expressions can be used in the field list of a Select, in Insert values, in Update assignments and in Where clauses.

  • Numbers: 10, -6, 3.14159
  • Strings: 'single quoted' or "double quoted". A doubled quote ('It''s') is not supported. A quote that follows a backslash does not end the string, but the backslash is kept: 'It's' returns It's.
  • Null: null


Operator Meaning
+ Adds numbers. When either side is a string, the values are concatenated: 'Id: ' + 5 returns 'Id: 5'.
- * / Subtraction, multiplication and division.
% Remainder (modulo).
Bitwise exclusive-or. Use Pow for exponentiation.
( ) Grouping, with standard order of operations.

A null on either side of + makes the result null (null propagation). Concat skips nulls instead.

These are used in Where clauses and join ON conditions:
Operator Meaning
= Equal (strings are compared without regard to case).
!= Not equal. The <> form is not supported.
> >= < <= Numeric comparisons.
LIKE, NOT LIKE Pattern matching, see Like.
BETWEEN, NOT BETWEEN Range matching, see Between.

Comparison operators can only be used in WHERE and ON clauses. Elsewhere, use the boolean functions such as IsEqual, IsGreater and IsLike, which return 1 or 0.

-- A line comment.
SELECT Id, Name FROM WordList:Language -- A trailing comment.
/* A block
   comment. */


Use Declare to define a variable for the rest of the script. Variables are referenced with an @ prefix. Applications using the client API pass parameters the same way, see Client.
DECLARE @Language = 2
SELECT Text FROM WordList:Word WHERE LanguageId = @Language


Every SELECT needs a FROM clause. To evaluate expressions that don't read any documents, select from the built-in Single schema, which contains exactly one document.
SELECT 10 + 10 as Twenty, 'Hello' + ' ' + 'World' as Greeting, Guid() as Id FROM Single




SQL :: IfNullNumeric
Returns the given number, or the default number when the given value is null.
SQL :: IIF
Short for "immediate if": returns whenTrue when the condition is true and whenFalse otherwise. The condition is usually one of the boolean functions such as [[IsEqual]] or [[IsGreater]].
SQL :: IndexOf
Returns the zero-based position of the first occurrence of textToFind in textToSearch, starting the search at offset. Returns -1 when it is not found.
SQL :: Insert
Insert creates new documents in a schema.
SQL :: IsBetween
Returns true (1) if the value is within the given range, including the range boundaries.
SQL :: IsDouble
Returns true (1) if the given value can be converted to a decimal number.
SQL :: IsEmpty
Returns true (1) if the given value is null or an empty string.
SQL :: IsEqual
Returns true (1) if the two given values are equal. The comparison is case-sensitive.
SQL :: IsGreater
Returns true (1) if the first value is greater than the second.
SQL :: IsGreaterOrEqual
Returns true (1) if the first value is greater than or equal to the second.